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| Titel |
Contributions of ectomycorrhizal fungal mats to forest soil respiration |
| VerfasserIn |
C. L. Phillips, L. A. Kluber, J. P. Martin, B. A. Caldwell, B. J. Bond |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 6 ; Nr. 9, no. 6 (2012-06-12), S.2099-2110 |
| Datensatznummer |
250007120
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| Publikation (Nr.) |
 copernicus.org/bg-9-2099-2012.pdf |
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| Zusammenfassung |
| Distinct aggregations of fungal hyphae and rhizomorphs, or "mats", formed
by some genera of ectomycorrhizal (EcM) fungi are common features of soils
in coniferous forests of the Pacific Northwest. We measured in situ respiration
rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir
forest in western Oregon to investigate whether there was higher respiration
from mats, and to estimate mat contributions to total soil respiration. We
found that areas where Piloderma mats colonized the organic horizon often had higher
soil surface flux than non-mats, with the relative increase in respiration
averaging 16% across two growing seasons. Both soil physical factors and
biochemistry were related to the higher surface flux of mat soils. When soil
moisture was high, soil CO2 production was concentrated into
near-surface soil horizons where mats tend to colonize, resulting in greater
apparent differences in respiration between mat and non-mat soils.
Respiration rates were also correlated with the activity of chitin-degrading
soil enzymes. This finding supports the notion that the abundance of fungal
biomass in EcM mats is an important driver of C and N cycling. We found
Piloderma mats present across 57% of the exposed soil, and use this value to
estimate a respiratory contribution from mats at the stand-scale of about
9% of total soil respiration. The activity of EcM mats, which includes
both EcM fungi and microbial associates, appeared to constitute a
substantial portion of total soil respiration in this old-growth Douglas-fir
forest. |
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